This invention relates to clutch mechanisms, and more particularly to an improved clutch mechanism for use in continuous variable transmissions. Even more particularly, this invention relates to an improved clutch bracket retainer or cam follower plate for a snowmobile drive system of the type which utilizes a torque sensing clutch.
Torque sensing clutches, for example the type employed in snowmobiles sold under the trademark ARCTIC CAT,are subjected to rigorous wear and tear, and as a consequence require frequent repair or replacement of parts. The subject matter of this invention concerns a torque sensing clutch mechanism of the type which includes a spring-loaded cam follower plate or bracket retainer, which has mounted thereon a plurality of cam followers that are designed to have sliding or rolling engagement with the ramps of an associated cam in response to variations in the torque applied to the mechanism.
Heretofore, as noted hereinafter, it has been customary for certain continuous variable transmissions (CVT) manufacturers to employ plastic buttons as cam followers in the torque sensing clutch mechanism of the transmission. The buttons are fixed to a retainer plate, or cam follower plate, and are designed to have sliding engagement with the camming surfaces on the associated cam ramps. Also, because such buttons tend to wear out rather quickly, and thus require frequent replacement, efforts have been made to improve upon the cam followers by utilizing, instead of the plastic buttons, roller followers mounted on needle bearings. However, the problem with the later development, as noted hereinafter, is that the roller followers that are mounted on needle bearings are very expensive; and the retainer plates which support the roller followers must be so modified that they require the use of special cams which differ in configuration from the cam employed in the original clutch mechanism.
It is an object of this invention, therefore, to provide for transmissions of the type described an improved clutch bracket retainer or cam follower retainer, which eliminates the need for employing plastic buttons as cam followers, and which also obviates the need for replacing the associated cam, when and if the cam retainer or follower plate is replaced.
Other objects of this invention will be apparent hereinafter from the specification and from the recital of the appended claims, particularly when read in conjunction with the accompanying drawings.